A hard disk generally comprises a housing having mounted therein: a magnetic disk; a read/write module for the magnetic disk; and a motor for driving the disk. The read/write module and the motor are connected to a control unit located inside the housing and connected to a pluggable connector secured to the housing. Since the operation of such a disk generates electromagnetic disturbances, grounding surfaces are provided on the housing, which surfaces are machined so as to be thoroughly plane and smooth, and each of them has a tapped well formed therein. The arrangement and the positioning of the grounding surfaces are standardized. The hard disk is fastened in the equipment for which it is intended by screws that pass through an electrically conductive chassis of the equipment and that are engaged in the tapped wells in such a manner as to establish electrical contact between the grounding surfaces and the conductive chassis that is itself connected to ground. Replacing the hard disk contained in the equipment with another hard disk requires action to be taken by a qualified person.
Proposals have been made to provide equipment having extractable hard disks. The housing of the hard disk is then screwed into a cradle provided with means for making a connection to the hard disk and to the electronic portion of the equipment, the cradle being removably received in the chassis of the equipment. Such equipment is not arranged to enable the hard disk to be replaced by a user having no particular technical knowledge.